What happens in a woman's body when she is sexually aroused, from initial excitement to after orgasm.

During arousal and sex, there are various stages of physical response. Researchers have identified four stages of sexual response in women and men: arousal, plateau, orgasm and resolution. This article describes what happens in a woman's body when she is sexually aroused.

Stage 1: sexual excitement or arousal

When a woman becomes aroused (turned on), the blood vessels in her genitals dilate. There is increased blood flow in the vaginal walls, which causes fluid to pass through them. This is the main source of lubrication, which makes the vagina wet.

The external genitalia or vulva (including the clitoris, vaginal opening, and inner and outer lips or labia) become engorged (swollen) due to the increased blood supply. Inside the body, the top of the vagina expands.

The pulse and breathing quicken, and blood pressure rises. A woman may become flushed, especially on the chest and neck, due to the blood vessels dilating.

Stage 2: sexual plateau

Blood flow to the lower third of the vagina reaches its limit, and causes the lower area of the vagina to become swollen and firm. This is called the introitus, sometimes known as the orgasmic platform, and undergoes rhythmic contractions during orgasm.

A woman’s breasts may increase in size by up to 25%, and blood flow to the area around the nipple (the areola) increases, making the nipples look less erect.

As a woman gets closer to orgasm, her clitoris pulls back against the pubic bone and seems to disappear. Continuous stimulation is needed in this phase to build up enough sexual excitement for orgasm.

Stage 3: orgasm

Orgasm is the intense and pleasurable release of sexual tension that has built up in the earlier stages, characterised by contractions (0.8 seconds apart) of the genital muscles, including the introitus. Read more here: what is an orgasm?

Most women don’t experience the recovery period that men do after an orgasm. A woman may have another orgasm if she's stimulated again.

Not all women have an orgasm every time they have sex. For most women, foreplay is an important role in an orgasm occurring. This can include stroking erogenous zones and stimulating the clitoris.